Replace HVAC now or later?

August 7, 2007 11:24 AM

Ten-year old air conditioner, busted compressor. Get a new compressor, or replace the whole thing?

Replacing the compressor will cost $1400; replacing the total HVAC will cost $3500. Allegedly, the compressor will get me five years more life before the whole thing goes out, while a new HVAC will last fifteen. If those numbers are accurate, and I'm not getting wildly overcharged (I'm in the DC area of the US), then I'm inclined to get the compressor, since my discount rate is greater than 11% (I'd rather spend $3500 in 2012 than $2100 now), but I'd like the collective wisdom of MeFi to let me know if those numbers are accurate. Also, whether those prices are reasonable enough that I shouldn't risk my girlfriend leaving me for someone with a working AC while I hunt around for a lower price.

posted by commander_cool to Home & Garden (7 answers total)

I'd imagine the new system would be much more energy efficient, so you could see the savings of total replacement on your electric bill.
posted by digiFramph at 11:31 AM on August 7, 2007 [1 favorite]

Does your utility co. have incentive plans for purchasing high efficiency AC? That might swing you one way or another. Is that what you mean by "discount rate", maybe?
posted by boo_radley at 11:47 AM on August 7, 2007

Best answer: Wow. I'm facing exactly the same decision as of last night. But a little further research echoes what digiFramph said. I'm taking into account the rather large electricity savings. I'm also taking into account a 10-year warranty on parts and labor that will allow me to cancel a service contract and save that money. I'm also taking into account the newer more environmentally-friendly coolant that we may all be forced to switch to in a few years. I'm leaning toward buying the new unit rather than just the compressor.
posted by lpsguy at 11:49 AM on August 7, 2007

Best answer: For what its worth, Consumer Reports says 10 years is the tipping point at which you should replace the whole unit.
posted by The Bellman at 11:56 AM on August 7, 2007

I would second the suggestion to look for external subsidies that would lower the cost of getting a new unit. Also, check the energy consumption of the new unit - many new units are considerably more energy efficient.
posted by GuyZero at 12:26 PM on August 7, 2007

Best answer: I suspect that once you factor in the energy savings from a newer, more efficient model, you'll find that it makes more sense to replace it. This explains air conditioner efficiency ratings. All you need to do is to find out the efficiency of your current unit, the efficiency of your new unit, and the cost of electricity in your area and off you go.
posted by ssg at 2:27 PM on August 7, 2007

Response by poster: Thanks. They're installing the new unit now.
posted by commander_cool at 8:17 AM on August 9, 2007